New chickens one sick and died..

We were given some chickens from a friend one of the 11 just died tonight 3 days after we got her. She got sick this am couldn't get up for food and water, was wobbly. Tonight she started gasping then died.. No wheezy sounds till the last few minutes. My friend had another chicken die 2 weeks ago, she thought it was egg bound. Could it be something contagious that takes that long to pass on? They are in their own tractor and are away from our birds..

No meds at all
They are on layer crumble and the bottom of the chicken tractor is dirt and grass, they are moved every day or every other day..

1) What type of bird , age and weight. Isa Brown.. 2-3 years old not sure exact age!
2) What is the behavior, exactly. She got sick yesterday am couldn't get up for food and water, was wobbly. Tonight she started gasping then died.. No wheezy sounds till the last few minutes. Her breast skin seemed blue tinged throughtout the day though..
3) How long has the bird been exhibiting symptoms? 1 day starting in am then died that night
4) Are other birds exhibiting the same symptoms? not that we can see yet! Though one was lost from this flock 3-4 weeks ago with somewhat similar symptoms
5) Is there any bleeding, injury, broken bones or other sign of trauma. She had been injutred by the previous owners dog about a month ago so her one leg didn't work great..
6) What happened, if anything that you know of, that may have caused the situation.
7) What has the bird been eating and drinking, if at all. Not eating the day she died, yes she was drinking
8) How does the poop look? Normal? Bloody? Runny? etc. Poop looked runny and yellow frothy yesterday
9) What has been the treatment you have administered so far? isolation, water and rest
10 ) What is your intent as far as treatment? For example, do you want to treat completely yourself, or do you need help in stabilizing the bird til you can get to a vet? Woudl like to know if this is potentially something that will pass to the other birds too!
11) If you have a picture of the wound or condition, please post it. It may help. She died last night
12) Describe the housing/bedding in use In a chicken tractor that has perches and nesting boxes, floor is open to ground, they are moved every day or other day